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GFRP Rock-bolt

GFRP fully threaded bar at its full potential

Dextra | GEOTEC GFRP Rock-Bolt | GFRP fully threaded bar at its full potential2

• Mine & Tunnel Support• Face Stabilization• Slope Protection• Temporary or Permanent Application

Key benefits

Light-weight = Easy handling and installation in the tunnelCut-ability = Faster excavation processCorrosion resistance = No premature bolt failure due to corrosion

Product selection matrix

Glossary

Standards Applications

Design

BS EN 1997-1

BS EN 1537

ACI 440-4R-04

Test

BS 7861-1

ACI 440-3R-12

Application method Temporary(Green)

Permanent(Orange)

Pre-grouted hole SolidECR + PE

SolidECR + VE

Injection through the bolt HollowECR + PE

HollowECR + VE

Type Descriptions

Solid Rock-BoltSolid Rock-Bolt is a rock-bolting system based on fully threaded

solid GFRP bar, and it is used for pre-grouted holes.

Hollow Rock-BoltHollow Rock-Bolt is based on fully threaded hollow GFRP bar,

and it works as a grouting pipe for post-injection.

Temporary Anchorage with a design life of less than 2 years (EN1537).

Permanent Anchorage with a design life of more than 2 years (EN1537).

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

CUT - ABILITY CUT - ABILITYCORROSION

FREE LIGHT WEIGHT

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About GEOTEC GFRP Rock-Bolt

GEOTEC FRP Solid Rock-Bolt can be installed with resin cartridges or forced into pre-grouted holes.

Features

System diagram

GEOTEC FRP Hollow Rock-Bolt are inserted into the hole and directly grouted through its hollow core.

• Fully threaded profile for optimum mixing and bonding properties.

• 2 in 1 system = Act as both. Anchor rod and grouting pipe.

• Standard range available in 4 diameters ranging from 25mm to 38mm.

• Can be delivered with GFRP (cuttable) or steel plate and nuts.

• Fully threaded profile for optimum mixing and bonding properties.

• 4 diameters available from 20mm to 32mm.• Available with chamfer to facilitate resin mixing

and prevent gloving.• Can be delivered with GFRP (cuttable) or steel

plate and nuts.• Steel coupler for extensions.

GEOTEC FRP Solid Rock-Bolt

* It is also suitable for pre-grouting boreholes installation.

GEOTEC FRP Hollow Rock-Bolt

1

2 2

1

Grouting

Resin cartridgefast reaction

Resin cartridgemedium/slow reaction

Cured resin

Dextra | GEOTEC GFRP Rock-Bolt | GFRP fully threaded bar at its full potential4

Temporary Application

Permanent Application

Temporary grade rock-bolt is a light-weight and economical solution for temporary tunnel support. It is made of polyester resin.

Permanent grade rock-bolt is a perfect alternative to steel rock-bolt. Designed for corrosive environments, it is made of acid/alkali-resistant vinyl-ester resin.

The below table is the result of the alkaline resistance test for accelerated aging. The tests were conducted in accordance with ASTM D7705M. The Vinyl Ester (Permanent Grade) GFRP bars are immersed in a 60°C alkaline solution (pH=12.7) for exposure times over 6 months. At specific intervals, the conditioned specimens are removed from the alkaline solution and tested as per standard ASTM D7205M for the residual tensile property of the bar.

The table shows that the Permanent grade rock-bolt retain over 85% of their tensile strength after being exposed to harsh alkaline environments for 50 years.

Alkali Resistance Testing Summarized Resultsof GEOTEC GFRP Rock-bolt

100.0% 100.0%

92.7%90.0% 90.1%

87.0%

y = -0.077ln(x) + 1.018R² = 0.875

60.0%

65.0%

70.0%

75.0%

80.0%

85.0%

90.0%

95.0%

100.0%

105.0%

Corrosion time(days)

30 60 90 1201 80

Natural life(years)

8.21 6.42 4.73 2.94 9.3

RESI

DUAL

STR

ENG

TH

Alkali pH=12.7-13.0 Log. (Alkali pH=12.7-13.0)

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Technical information

Accessories

Solid BarPhysical Properties Mechanical Properties (T) Mechanical Properties (P)

OD Nominal Dia.

Nominal CSA Pitch Temporary

Ultimate Tensile Load

Ultimate Tensile

StrengthPermanent

Ultimate Tensile Load

Ultimate Tensile

Strength

(mm) (mm) (mm²) (mm) Resin/Glass (kN) (MPa) Resin/

Glass (kN) (MPa)

20 16 200 10 PE/ECR 200 1000 VE/ECR 200 100022 18 250 10 PE/ECR 250 1000 VE/ECR 250 100025 21 350 10 PE/ECR 350 1000 VE/ECR 350 100032 27 580 10 PE/ECR 560 960 VE/ECR 560 960

Hollow BarPhysical Properties Mechanical Properties (T) Mechanical Properties (P)

OD x ID Nominal Dia.

Nominal CSA Pitch Temporary

Ultimate Tensile Load

Ultimate Tensile

StrengthPermanent

Ultimate Tensile Load

Ultimate Tensile

Strength

(mm) (mm) (mm²) (mm) Resin/Glass (kN) (MPa) Resin/

Glass (kN) (MPa)

25 x 12 N/A 250 10 PE/ECR 180 720 VE/ECR 220 88028 x 12 N/A 350 10 PE/ECR 260 740 VE/ECR 320 90032 x 15 N/A 365 10 PE/ECR 280 765 VE/ECR 350 100038 x 20 N/A 500 10 PE/ECR 400 800 VE/ECR 500 1000

Item Images Usage

Domed Plate + Domed Nut GFRP accessories for angle compensated support which allows inclination

Swivel Plate + Swivel Nut GFRP accessories for straight 90 degree angle support

Flat Plate + Flat Nut Steel accessories for straight 90 degree angle support

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GEOTEC GFRP Rock-bolt brochure - Mar 2021 - WK

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